cheese on toast = speed of light

Dara O'Briain's BBC Science Club on BBC 2 tonight calculated the speed of light by crudely measuring the regular wave indentations [~60mm apart] in cheese-on-toast in a microwave against the wavelength of the microwave. Result in studio ~320,000km/s eg 7% fast

Note the microwave turntable was removed to avoid smearing the microwave indentations.